The Isotropic Initial State: How Quantum-Geometry Dynamics Dissolves the Foundational Problems of Standard Cosmology

The three foundational problems of standard cosmology — the horizon problem, the flatness problem, and the cosmological constant problem — are standardly treated as independent empirical puzzles each requiring its own solution. This paper argues that they share a single cause: the import of a continuous spatial manifold with a singular initial state. When the foundational assumption is replaced — when space is constituted not by a smooth Riemannian manifold but by a finite discrete preonic structure, as in Quantum-Geometry Dynamics (QGD) — all three problems are dissolved simultaneously, not by separate mechanisms but by the removal of their common cause. The initial state of the QGD universe is the Isotropic Initial State S₀: a uniform preonic configuration in which the field density ρ (r) = N⁺ (r) /N⁻ (r) is identical across all spatial regions, there is no preferred direction, and there is no singularity. This state is not a postulate; it is the unique state of minimum complexity consistent with the QGD axioms before any causal succession has generated an asymmetry. The horizon problem cannot arise because initial isotropy is not a fine-tuned coincidence but an axiomatic necessity. The flatness problem cannot arise because a uniform isotropic initial preonic state corresponds precisely to flat spatial geometry in the emergent large-scale description — flatness is not fine-tuned from a continuous parameter space; it is the direct description of the maximum-symmetry element of a finite discrete state set. The cosmological constant problem cannot arise because there is no continuum of vacuum field modes whose zero-point energies generate a divergent vacuum energy; the 120-order-of-magnitude discrepancy between QFT's prediction and observation is a consequence of the continuum, and that continuum has no referent in the discrete preonic framework. The observed accelerated expansion is accounted for by n-gravity — the repulsive component of the axiom-derived two-force structure, dominant beyond the threshold distance dΛ — whose effective cosmological constant is determined by the QGD coupling constants rather than fine-tuned. The inflationary programme is evaluated as a response to problems generated by the continuum rather than to independently motivated physical puzzles. The inflaton field, reheating, and the graceful exit problem are each shown to be non-minimal assumptions introduced to suppress consequences of the singular continuous initial state. The canonical Starobinsky R+R² model is now under observational tension from ACT DR6 combined with DESI BAO data (arXiv: 2506. 20707), consistent with the expectation that no single inflationary model provides a uniquely satisfactory fit when the inflaton potential is a free function rather than a derivation from first principles. Structure formation in QGD proceeds entirely deterministically from S₀ via the three-dimensional trajectory mechanism: preons (+) propagating in all directions simultaneously from the uniform initial distribution converge through p-gravity binding at all transverse separations d in dₘin, dΛ, producing a near-scale-invariant mass function of bound structures — the primordial power spectrum — without quantum fluctuations, without inflation, and without reheating. The slight red tilt (nₛ 6–10 are at smaller true distances and more recent lookback times than ΛCDM infers, fully consistent with p-gravity's simultaneous multi-scale condensation from S₀; (b) the CMB last-scattering surface is at a substantially smaller true Doppler-recession distance than z ≈ 1100 implies, shifting predicted acoustic peak positions in a quantitatively constrained way; (c) the Hubble tension — H₀ ≈ 73 km/s/Mpc locally vs. ≈ 67 km/s/Mpc from the CMB — is the expected structural consequence of applying a single-component redshift formula when the physical mechanism has two dominant components at different redshift regimes, not an anomaly requiring new physics. The paper situates the QGD dissolution against bouncing cosmologies, causal set cosmology, loop quantum cosmology, and string cosmology, showing that each retains either the continuous manifold (and therefore the vacuum energy problem) or fails to provide an axiomatic derivation of the dynamics producing structure formation. Part of the QGD / MPDT publication programme. Foundation: Quantum-Geometry Dynamics book P11, DOI: 10. 5281/zenodo. 19584666. Companion cosmology paper: P13 DOI: 10. 5281/zenodo. 20301995. Redshift formula: P33 DOI: 10. 5281/zenodo. 20532256. Empirical grounding programme: P14 DOI: 10. 5281/zenodo. 20369889. Observational tensions: P29 DOI: 10. 5281/zenodo. 20215090.